Apparatus for subliming sulphur



Aug. 19, 1930. E. F. WHITE 1,773,56

APPARATUS FOR SUBLIMING SULPHUR Filed Nov. 13, 1924 2 Sheets-Shee 1 INVENTQR.

ZZZZJLWZZ m2 7 6 MG W Aug. 19, 1930. E. F. WHITE v APPARATUS FOR SUBLIMING SULPHUR 2 Sheets-Sheet 2 Filed NOV. 13, 1924 I INVENTQR. Emma/mail? Wm M w 25 showing the construction of Patented Aug. 19, 1930 UNITED STATES PATENT OFFICE EDWARD F. WHITE, OF ROCHESTER, N EW YORK APPARATUS FOR SUBLIMIN G SULPHUR Application filed November 13, 1924. Serial No. 749,674.

This invention relates to methods and apparatus for subliming sulphur to produce the so-called flowers of sulphur of commerce,

and has for one of its objects the provision of 5 a continuous, accurately controlled and eflicient method of sublimation, together with.

practical and reliable apparatus for accomplishing the same. A further ob ect is to provide a rapid, economical and safe method and apparatus for cooling sulphur vapors from a retort under accurately controlled conditions adapted to produce a uniform and superior quality of flowers of sulphur.

To these and other ends the invention resides in certain improvements and combinations of parts, all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings:

Figure 1 is a general view, partly diagrammatic in character, showing an apparatus embodying the present invention; and

Figure 2 is a sectional perspective view the sulphur receptacles, retort and cooling chamber.

Similar reference numerals throughout the several views indicate the same parts.

The present invention comprises both a method of sublimation and also an apparatus for carrying out the same and as the method can be disclosed to best effect in connection with the description of the apparatus and its operation, the latter will be first described.

The apparatus comprises, generally speaking, a retort adapted to afford a substantial vaporizing surface and communicating below the level of such surface with a receiver into which the sulphur is fed and melted in order to supply the retort. The latter is provided also with means for directing a continuous current of gas over the vaporizing,

surface at a relatively high velocity for immediately diffusing the generated vapor and carrying the same into a cooling device or chamber. The gas employed for this purpose is preferably of an inert character, such as CO or S0 and the diffusion of the generated vapor with the current of cool inert gas and immediatesubjectionofthemixturetothe action of the coolingchamber resultsinaquick reduction in the temperature ofthe vapor with the result that it is converted directly into the desired powdered state known as flowers of sulphur. The gas supply means for the retort and the cooling chamber are connected in a continuous circulating system or circuit provided with means for maintaining circulation of the gas as described and this closed circulating system comprises also a means for maintaining a constant suitable ressure in the system by the supply or withdrawal of gas for accurately controlling the process and maintaining the conditions best suited to efficiency and quality in the product.

Referring more particularly to the drawings there is shown at 10 a retort preferably in the form of ametal container 11 mounted in a furnace 12 over a fire pot 13 for directly heating the bottom of the retort. At 14 is a flue through which the products of combustion are carried under the bottom of an opentopped receptacle or receiver 15 to which the sulphur to be'sublimed is fed. The receptacle is connected by a pipe 16 with the retort purpose of directing a current or sheet of gas at relatively high velocity di- 'rectly over and adjacent the vaporizing surface for diffusion with the vapor as it is generated and for sweeping it into the discharge passage 17, the retort is provided with a nozzle means in the present instance in the form of a pipe 19 extending across the retort above the sulphur level opposite the discharge pas-' sage 17 and having on the side toward the retort a slot or series of openings extending longitudinally of the pipe for directing a current of gas across the retort toward the discharge passage. The pipe isconnected with an external pipe 20 leading to a gas circulating systemas hereafter described.

The cooling chamber into which the sulphur vapor is swept by the gas current is shown at 21 as preferably in the form of a sheet metal container of substantially rectangular shape having its bottom 22 convergent from the sides downwardly toward a cylindrical trough 23 for collecting the products of sublimation. A propelling worm of known variety may be provided in the trough and rotated by a belt pulley 24 for discharging the collected sulphur through an outlet 25 controlled by a gate valve 26. These parts may have any known or suitable construction so that a detailed description thereof appears unnecessary but it will be understood that this discharge means is of such a nature as to be air tight for preventing escape of the circulating gas or entrance of the atmosphere into the chamber. For this purpose the discharge spout 25 may be curved upwardly as shown to retain therein a suflicient supply of sulphur to close it while valve 26 is open for discharging the sulphur into a container indicated at 27 The chamber 21 is provided with means for cooling the same in the present instance in the form of a jacket 28 enclosing a substantial part of the chamber surface. The discharge conduit 17 of the retort is connected by means of a conduit 29 with the interior of thechamber and the intake for the chamber jacket is preferably through a sleeve 30 extended around the discharge conduit toward the retort for cooling the conduit also. Circulation of air through the chamber jacket is effected by a pump or blower 31 connected with the jacket at the other side of the chamber as by a pipe 32.

The gas supply nozzle for the retort is connected with the cooling chamber by continuous conducting means provided with a device such as a pump for maintaining continuous circulation of the gas therethrough. To this end there is provided a pipe 33 provided with a relief valve communicating with the top of the cooling chamber opposite the connection with the retort and leading to a pump 34 which may be of any known or suitable variety adapted for circulating the gas. The discharge 35 of the pump is carried through a suitable screening or dust removing device indicated generally at 36 from which the gas is carried through a valved pipe 37 to a filter or moisture removing device and indicated generally at 38. The latter may be of any suitable known character and is connected by a valved pipe 39 with a line 40 which is also connected directly with the pipe 37 and controlled by a valve as at 41 for bypassing the moisture filter 38 when desired. The line 40 is carried through a reserve gas holder 42 from which a line 43 is carried to the retort nozzle pipe 20.

The gas holder 42 is preferably of the automatic gas-bell type comprising an inverted bell or container 44 sliding telescopically in the main shell of the holder 42 and counterbalanced by adjustable weight means 45.

.The open bottom of the bell 44 dips into a liquid seal preferably of an inert variety such as an oil. The ipes 40 and 43 communicate with the interior of the bell 44 and it is apparent that the latter is adapted to rise and fall in the well known manner in response to the pressure in the system for receiving gas from and supplying gas to the latter as its pressure rises and falls and to thus maintain the pressure substantially constant.

An additional regulating means is preferablyprovided in the form of a throttling, valve of any suitable known construction indicated generally at 46 in the pipe 33, the valve having an operating arm 47 pivotally connected by a link 48 with one end of the lever 49 pivotally supported at 50. The other end of lever 49 is connected witha stem 51 of a pressure responsive diaphragm motor 52 of a well known construction the chamber of which is connected by a pipe 53 with the cooling chamber. As the pressure of the latter tends to becolne excessive the diaphragm means 52 is operated to swing lever 49 and open valve 46 more fully to increase the relief of pressure by the pump 34. Vice versa, when pressure in the chamber drops, valve 46 is adjusted to throttle the connection with the pump and maintain the pressure.

Means are provided for disconnecting the gas holder from the system in case of the excessive rise of the gas bell, comprising twoway valves 54 and 54 located in pipe lines 40 and 43 respectively. These valves are adapted to shunt the flow of gas from the gas holder through the pipe line 56 and are operated automatically when the bell 44 of the holder rises to an extreme position for which purpose the valves are provided with operating arms 57 and 57 pivotally connected with a link or rod 58 extending vertically at one side of the holder as shown. The upper end of the rod is pivotally connected as at 59 with a lever 60 ivotedat 61 on a bracket 62 on the holder rame. The other end of lever 60 projects into the path of movement of a lug 63 on bell 44. Lever 60 is also provided with an overthrow weight 64 of the well known character for swinging the lever past a central position and maintaining it yieldably in one or the other of its extreme positions. As the gas bell rises the lever is engaged by the lug 63 and swung to depress link 58 and adjust valve 54 to shut off the gas holder and complete the circuit through the pipe 56. Upon restoration of normal conditions in the system these parts may be returned by hand to the normal position shown in the drawings. At 65 is a valved pipe line for connecting the system with a suitable source of inert gas for initially filling and replenishing the system as may be required from time to time.

It is apparent from the above description .ler.

of the various parts of the system and their functions that the system may be initially filled with the inert gas through connection 65, the gas, being passed through the moisture remover 38 to insure a thoroughly dry condition. With the system thus filled with a dry inert gas and this gas put in circulation by operation of pump 34, the vaporization of the sulphur in retort 10 is started. As the vapor is generated the flow of gas across substantially the entire vaporizing surface immediately sweeps the vapor into the cooling chamber the effect of which, with the initial cooling of the vapor by diffusion with the gas, is to rapidly convert the vapor directly into powder form without formation of liquid sulphur owing to the rapid cooling and complete and accurate control of the ressure and temperature conditions afforded y the apparatus. The flowers of sulphur thus formed are deposited upon the floor of the cooling chamber and collected in the trough 23 from which they are removed from time to time as may be required by opening gate valve 26 and driving pulley 24 to operate the propel- Pump 31 is kept in operation during the process to continually circulate air through the coolingchamber Jacket to cool the chamber and the connection of the latter with the retort. The pressure in the system is at all times under the automatic regulating action of the gas holder and the diaphragm device 52 operating the throttle valve 46. Slight variations of pressure in the chamber due to changing ratio of sublimation or temperature raises or lowers the bell 44 which thus provides for expansion and at the same time supplies additional gas upon the fall of the pressure and constantly maintaining a slight pressure in the system in excess of that of the atmosphere. Changes of pressure in the cooling chamber are also taken care of, especially when of a sudden nature, by the automatic operation of theauxiliary throttle valve 46 connecting the chamber with the pump.

The efficient sublimation of sulphur requires favorable vaporizing conditions in the retort and complete and accurate control of the generated vapor for rapidly cooling the same through the range of temperature required to convert it directly into powder form. Sulphur produces a relatively heavy vapor which requires a definite amount of energy to elevate and transfer the same to the cooling chamber and the rapidity of vaporization depends to a degree upon removal of the generated vapor from above the surface of the liquid. One advantage of the present process and apparatus resides in the efiicient accomplishment of the desired operation in this'respect through the maintenance of the gas stream across the sulphur surface for sweeping the vapor from the latter and over into the cooling chamber. By this means a substantialy constant vaporizing action is maintained, while the circulating gas tends by its difi'usion with'the sulphur to assist in the coolin of the later and in distributing it in a diflused state in the cooling chamber as desirable for uniform sublimation in a finely powdered and homogeneous state. The use of an inert gas to the exclusion of all air has the additional advantage of eliminating all possibility of explosions of the vapor frequently resulting from mixture 7 of the latter with the atmosphere, and the maintenance of the pressure in the system slightly above that of the atmosphere prevents any tendency of the air to enter the sys' tem.

A further important feature lies in the constant connection of the system with a reserve supply of gas through automatic means permitting expansion of the gas, the supply of gas to the system when needed and the automatic maintenance of a slight pressure on the system at all times. The generation of sulphur vapor in the retort tends of course to produce rapid increase in pressure in the latter which may be greatly accelerated by fluctuating conditions of pressure in the system. The resultant variations in pressure materially efl'ect the sublimation rocess and the uniformity of conversion of the vapor into powder form. The provision of an automatic holder for the reserve gas such as described effectively overcomes such difficulties in that it takes care of pressure variations in an elastic manner insuring a constant flow of an adequate quantity of gas through the retort and the consequent regulation of both the vaporizing andsolidifying processes. Asimilar beneficial result is obtained through the automatic regulating means comprising the throttling valve 46 which supplements the action of the gas holder.

The invention thus provides an eflicient and reliable method of sublimation particu- Iarl adapted for the commercial production of tihwers of sulphur on a substantial scale, as well as a thoroughly practical and complete apparatus for carrying out the process and affording economically a comparatively high quality of product.

I claim as my invention:

1. In apparatus of the character described,

a retort affording a substantial vaporizing surface for a substance contained therein, a cooling chamber, and means comprising a conducting circuit for continuously circu- 190 lating a body of inert gas through said retort and chamber provided with nozzle means for directly sweeping said vaporizing surface with said gas for immediately diffusing the generated vapor and carrying the same into said cooling chamber.

2. In apparatus of the character described,

a vaporizing retort, a chamber provided with a jacket and with means for circulating a cooling medium through said jacket, a

closed conducting circuit connecting said retort and chamber and provided with nozzle means for directing a gas immediately over the vaporizing surface of said retort, means for continuously circulating an inert gas through said circuit to diffuse and carry the generated vapor into said chamber, and a gas holder in said circuit provided with means for maintaining a constant pressure therein.

3. In apparatus of the character described, a vaporizing chamber, a receiver for a substance to be sublimed communicating with said retort below the vaporizing surface, a chamber provided with means for cooling the same, a closed conducting circuit connecting said retort and chamber and provided with nozzle means for sweeping the vaporizing surface with a current of gas, means for continuously circulatingan inert gas through said circuit to diffuse and carry the generated vapor into said chamber, means in said circuit for removing moisture from said gas, and a regulating gas holder in said circuit adapted to automatically maintain the pressure constant therein.

4. In apparatus of the character described,

' a vaporizing chamber, a receiver for a substance to be sublimed communicating with said retort below the vaporizing surface, a chamber provided with means for cooling the same, a closed conducting circuit connecting said retort and chamber and provided with nozzle means for sweeping the vaporizing surface with a current of gas, means for continuously circulating an inert gas through said circuit to diffuse and carry the generated vapor into said chamber, valve means governing said circuit, and a controller connected with and responsive to the pressure in said chamber for automatically controlling said valve means.

EDWARD F. WHITE. 

